Shape discrimination vision assessment and tracking system

ABSTRACT

A handheld vision tester and a method of self-testing vision of a user of the handheld vision tester are provided. The method ensures that a display of the handheld vision tester is within an acceptable distance to eyes of the user. Variations of the acceptable distance are compensated for. The method further displays different shapes, either dynamically or statically, on the display to the user. The method also allows for input to the handheld vision tester by the user in response to the different shapes displayed. Results of the self-test are determined from the inputs to the handheld tester by the user.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application Ser.No. 61/176,885, filed by Michael Bartlett, et al. on May 9, 2009,entitled “Shape Discrimination Vision Assessment System,” incorporatedherein by reference. This application also claims the benefit of U.S.Provisional Application Ser. No. 61/251,159, filed by Michael Bartlett,et al. on Oct. 13, 2009, entitled “Shape Discrimination VisionAssessment System,” also incorporated herein by reference.

TECHNICAL FIELD OF THE INVENTION

This invention relates to techniques for the design and implementationof a vision testing and assessment system.

BACKGROUND OF THE INVENTION

Vision assessment today is most commonly carried out either with basicscreening charts or by professional evaluation by a trained optometristor ophthalmologist. Many well known screening tests are available. Thewell-known Snellen acuity chart is widely used, but other charts such asthe “tumbling E” chart, the “Landolt C” chart, and the Amsler grid chartare also commonly used. Use of vision charts is suitable for analysis ofcommon vision problems such as focusing disorders, but they are oflimited value for monitoring more serious disorders such as diabeticretinopathy, age-related macular degeneration, and other seriousdisorders. These diseases have the potential to become active anddegenerate rapidly. If not properly treated, permanent vision loss oreven blindness may occur.

Of course, methods exist for diagnosing and treating these more seriousconditions. However, they generally require expensive and sophisticatedequipment that must be operated by a specially trained technician, suchas an optometrist or an ophthalmologist. In fact, the only commonlyavailable tool for self-monitoring of most retinal disorders is thepaper Amsler grid test. The Amsler grid is simply a square grid ruled onpaper or cardboard. The user tests each eye individually by fixating onthe grid and noting any grid segments that appear to be missing, wavy,or distorted. While simple and low cost, the Amsler grid is difficult touse since the individual must subjectively assess their own condition,it is not quantitative, and it can be very hard for patients todetermine if missing, wavy, or distorted grid segments are slightly moreor less pronounced from one test to the next.

Hence, a low cost vision screening and assessment system that can detectthe early signs of vision disorders, track their progress, and/or assesstheir relative severity is highly valuable. Such a system would allowpersons to test their vision for serious vision disorders such asmacular degeneration, diabetic retinopathy, glaucoma, and otherdisorders. Persons suffering from such disorders could use such a systemto track their condition and validate the effects of their treatment inan objective and quantitative manner. And, of course, objective andquantitative vision testing can also be very useful to care providers inoptimizing treatments for their patients.

SUMMARY OF THE INVENTION

To address the above-discussed deficiencies of the prior art, in oneembodiment, there is provided a method to self-test vision of a user foruse with a handheld vision tester. In this particular embodiment, themethod comprises: ensuring that a display of the handheld vision testeris within an acceptable distance to eyes of the user; displayingdifferent shapes on the display to the user; allowing for input to thehandheld device by the user in response to the displayed shapes; anddetermining results of the self-test from the inputs to the handhelddevice by the user. Variations of the acceptable distance arecompensated for. The different shapes are displayed statically ordynamically.

In another embodiment, there is provided a handheld vision tester forvision self-testing by a user. The handheld vision tester comprises adisplay, interface port, camera, microphone, speaker, and cursorcontrol. The display is configured to present different shapes, witherstatically or dynamically, to the user for the vision self-testing. Theinterface port is configured to transmit results of the visionself-test. The camera is configured to ensure eyes of the user arewithin an acceptable distance to the display, wherein variations of theacceptable distance are compensated for. The microphone is configured toallow the user to control the handheld vision tester with voice or soundcommands. The speaker is configured to send messages and information tothe user. The cursor control is configured to allow the user to inputresponses to the displayed different shapes, trigger operations of thehandheld vision tester, and control the handheld vision tester.

The foregoing has outlined various features of the invention so thatthose skilled in the pertinent art may better understand the detaileddescription of the invention that follows. Additional features of theinvention will be described hereinafter that form the subject of theclaims of the invention. Those skilled in the pertinent art shouldappreciate that they can readily use the disclosed conception andspecific embodiment as a basis for designing or modifying otherstructures for carrying out the same purposes of the invention. Thoseskilled in the pertinent art should also realize that such equivalentconstructions do not depart from the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the invention, reference is nowmade to the following descriptions taken in conjunction with theaccompanying drawings, in which:

FIG. 1 a shows a handheld device suitable for running a vision test;

FIG. 1 b shows an image of a user's face including key dimensions thatmay be used to determine the distance the user is away from the cameraused to collect the image;

FIG. 2 a shows a Landolt C image for vision testing;

FIG. 2 b shows an Amsler grid image for vision testing;

FIG. 2 c shows an image for vision testing, including a reference circleand a circle with a modulated region;

FIG. 3 a shows an image for vision testing made up of multiple shapes inwhich one shape, a circle, is different from the other two, which arehexagons;

FIG. 3 b shows an image similar to the one of FIG. 3 a, but where theshapes have been moved to other locations on the screen to avoidcreating a point of fixation;

FIG. 4 a shows a circle with pre-defined contrast as a function ofradial dimension;

FIG. 4 b shows a modulated circle with pre-defined contrast as afunction of radial dimension;

FIG. 5 a shows a first three-way selection test with two circles and onemodulated circle, all the shapes having pre-defined contrast as afunction of radial dimension, and the modulated circle having strongmodulation;

FIG. 5 b shows a second three-way selection test with two circles andone modulated circle, all the shapes having pre-defined contrast as afunction of radial dimension, and the modulated circle having moderatemodulation;

FIG. 5 c shows a third three-way selection test with two circles and onemodulated circle, all the shapes having pre-defined contrast as afunction of radial dimension and the modulated circle having slightmodulation;

FIG. 6 shows a flow chart showing some elements of how a vision testroutine may be controlled;

FIG. 7 a shows a graphical result of a shape discrimination vision test;

FIG. 7 b shows a graphical result of a shape discrimination vision testthat includes freebies;

FIG. 8 a shows a quantitative result presentation for a shapediscrimination vision test;

FIG. 8 b shows a numerical example of a quantitative result presentationfor a shape discrimination vision test; and

FIG. 8 c shows a logMAR gray scale result presentation.

DETAILED DESCRIPTION

In FIG. 1 a, an electronic handheld device 100 is shown. The handhelddevice 100 may include a case 102, a display 104, a cursor control 110,a fingerprint sensor 114, a camera 112, a first button 106, a secondbutton 108, a speaker 120, a microphone 122, a power connector 116, andan interface port 118. The display 104 may include touch-screen and/ormulti-touch capability so that the handheld device 100 may be controlledby touching the display 104 in various locations or manners withincertain timeframes. The fingerprint sensor 114 allows the handhelddevice 100 to identify the person using it (referred to as a user).Other techniques for positive identification such as voice analysis,passwords, biometric analysis, photographic analysis, and other possibletechniques may also be implemented in the handheld device 100. It isalso possible to positively identify the specific handheld device 100that was used to take a specific test by recording an identifying numberor code specific to that handheld device 100 with the records for thattest. In addition, the identifying number or code for the specifichandheld device 100 might be beneficially marked or engraved somewhereon or inside the case 102 or other location of the handheld device 100.Additional information regarding the user or the specific handhelddevice such as its date code, manufacturing date, serial number, andother information might also be beneficially marked, engraved, orotherwise indicated on or inside the handheld device 100. Warningmessages, reminders, safety warnings and other information may also bemarked on or inside the case 102. The cursor control 110 is a buttonthat may be pressed to move a cursor across the display 104 and positionit in a desired location. Pressing the cursor control 110 may also beused to trigger operations and to control the handheld device 100.Alternative implementations of cursor controls including track balls,joysticks, touch pads, and other approaches may also be used in place ofthe cursor control 110 as shown in FIG. 1 a. The first button 106 andthe second button 108 may be used to control the handheld device 100 andto operate functions of the handheld device 100. It is noted that thehandheld device 100 may be operated through manipulation of the display104 if a touch-screen or multi-touch capability is included, through thecursor control 110, through the fingerprint sensor 114, through thefirst button 106 and through the second button 108. Additional buttonsand controls are possible including buttons and controls on the sidesand back of the handheld device 100. It is also possible that thehandheld device may include only one button, or no buttons at all. Inaddition, some embodiments of the handheld device 100 may includeaccelerometers, gyroscopes, or tilt sensors to monitor motion, rotation,and orientation of the handheld device 100 so that the handheld device100 may be responsive to how it is held and physically oriented ormoved. As a simple example, the use of a tilt sensor would allow thedevice to monitor and/or respond to it's orientation to preferentiallyuse the display 104 in a portrait or landscape orientation. The handhelddevice 100 may also include a microphone 122 and audio processingcapability to so that voice or sound commands may be used to control it.Also, the handheld device 100 may include a speaker 120, buzzer,vibrator, or other audible or physical signaling devices so that it cansend messages and information to the user. Audible commands may benefitfrom use of a volume control that could be adjusted through the handhelddevice's 100 user control functions. And the camera 112 may be used toobserve gestures, signals, sign language, and other symbols andmovements of the user to control the handheld device 100 as well.Gestures involving actual motion of the handheld device 100 may bemonitored with a motion sensor, accelerometer, or other techniques. Itis also possible to include additional buttons, displays, an externalmouse or trackball, and other forms of input devices. It is also notedthat haptic, audible, or other feedback such as a click, buzz,vibration, jog, or other signal delivered on each button press,touch-screen or multi-touch press, or other activation of an inputmechanism to the handheld device 100 may be beneficial to acknowledgethe user's input and assure them that the handheld device 100 has orwill respond to their inputs.

The case 102 of the handheld device 100 may be constructed from metals,plastics, or other materials. While not shown in FIG. 1 a, the handhelddevice 100 may include removable panels on its front, back, or sides toallow batteries, memory cards, or optional accessories to be installed,connected, or removed. The power connector 116 allows the device to bepowered from an external electrical power source that may supply AC orDC power to the handheld device 100. Some interface ports 118 (such asUSB—Universal Serial Bus) may also be capable of supplying power to thehandheld device 100. Interface port 118 allows the handheld device 100to be connected to an external host computer, external cameras, externalcalibration or test equipment, external accessories, or other systems ordevices the user may desire to connect it to. It is also possible thatthe interface port 118 or the power connector 116 could be configured tosupply battery power from the handheld device 100 to an external deviceor interface connected to them. The interface port 118 may beconstructed from multiple physical interfaces and protocols. Someexamples are Universal Serial Bus (USB), P1394, Ethernet, RS232, andmany other possible interfaces. In addition to the interface port 118,the handheld device 100 may include wireless connectivity. Bluetooth,IEEE802.11, Zigbee, and many other wireless communications protocols andradio electronics may be included in the handheld device 100. The wiredand or wireless connectivity of the handheld device 100 allows it tosend information to a network service, host computer, or other computingdevice; and also allows for calibration, configuration, test protocols,software updates, and other useful information to be sent from a hostcomputer or other data processing device or interface to the handhelddevice 100. The procedure for allowing the handheld device 100 to eithersend data out over its wired or wireless interfaces or to receiveinformation from other sources should normally include security featuresto ensure that the user's information and privacy are not compromisedand also to ensure that configuration, calibration, and other importantfactors of the handheld device 100 operation cannot be compromisedillicitly or accidentally.

The handheld device 100 may be beneficially battery operated so that itcan be used in a portable fashion in many locations when and where it isconvenient for the user. Additionally, the handheld device may use powersupplied to it over the interface port 118, the power connector 116,through wireless power sources, or through other possible ways ofprovide power to the handheld device 100. In the case of operation froman internal or external battery, the handheld device 100 maybeneficially include capability to alert the user of the amount ofcharge available from the battery and alert the user when batterycharging is needed. The handheld device 100 may also check the batterylevel before a vision test is begun to ensure that adequate energy isavailable to complete the test so that a test is not interrupted due toloss of power. The handheld device 100 may also include softwareroutines constructed so that in the event of a sudden power loss theinformation stored in the handheld device 100 such as prior vision testresults and other information is not corrupted or lost.

In this embodiment, the handheld device 100 is used to provide a visiontest suitable for detected eye diseases and to monitor their presentstatus or severity. As some vision tests are sensitive to the distancefrom the user under test to the display device being observed, it may beimportant that the handheld device 100 operate in a fashion that ensuresthat each test sequence is undertaken at an appropriate viewingdistance. There are several options for how this can be achieved. First,the camera 112 may take a picture or even continuously monitor a videosequence of the user and make appropriate measurements from the image toensure that the user is at an acceptable distance from the handhelddevice 100. An example of use of a camera image 150 to determine viewingdistance is illustrated in FIG. 1 b. In FIG. 1 b, a camera image 150 ofa user's face 154 is shown inside the camera's 112 image boundary 152. Ahorizontal image dimension 156 and vertical image dimension 158 areshown. Dimensions between some features of the user's face 154 are alsoshown. These are the distance between the pupils 160, the distancebetween the outer eye sockets 162 and the dimension between the pupilsand the bottom of the nose 164. It is noted that for the purposes hereof determining viewing distance that dimensions of the user's face 154that are substantially unchanged by dress, mood, hairstyle, or othervariable factors are preferred. That is, dimensions such as the distancebetween the pupils 160 are preferred over more variable dimensions suchas the opening between the sides of the user's hair. Of course, manyother dimensions of a user's face 154 may be used in addition to thoseshown specifically in FIG. 1 b. By monitoring the distance between thepupils 160 or other dimensions of the user's face 154; and with theknowledge of the magnification afforded by the camera's 112 optics, itcan be readily computed whether the user is a suitable distance from thehandheld device 100. Such a technique for monitoring the distance theuser is from the handheld device 100 may benefit from calibrating theactual dimensions of the user's face 154 to be used before testingbegins. That is, if the handheld device 100 takes a photograph of theuser when the user is at a known distance from the handheld device 100,then the handheld device 100 can compensate for the actual size of thefacial features of a specific user and more accurately estimate thedistance the user is subsequently from the handheld device than wouldotherwise be possible. Alternatively, the camera 112 optics could becalibrated against an object of known physical size, for example aruler, placed at a know distance from the camera so that a referenceimage can be collected against which images may be compared. It is notedthat the size of a dimension of the user's face 154 (or any other objectfor that matter) in a camera image 150 may not be a linear function ofthe distance it is from the camera 112. Consequently, use of non-linearcorrection factors or look-up tables may be beneficial in accuratelycomputing the viewing distance from analysis of a given image 150. Ofcourse, if the camera 112 includes a zoom capability or other variableoptics, it may be beneficial to take distance measurements with thecamera 112 set to a known and fixed level of zoom every time suchmeasurements are taken. Alternatively, variations in zoom could beaccounted for in the distance computation.

Of course, many other methods for measuring the distance from thehandheld device 100 to the user are possible. Sonar, radar, light-basedsystems, and other electronic and photonic distance measurement devicescan be incorporated into embodiments of the handheld device 100 toprovide this function. Even simple mechanical techniques such astelescoping mechanical elements, strings that can be held from the userto the device, extendable chin rests, and many other techniques may beincorporated in to the handheld device 100 to ensure the user undertakestesting at an appropriate viewing distance.

If the handheld device 100 detects that the user is not at a suitabledistance for the test that is operating, the handheld device 100 maysignal to the user through a visible, audible, or other way that he orshe is either too close or too far away. The handheld device 100 may notcontinue operation of the testing until the user has positioned himselfor herself at an appropriate distance so that accurate and reliabletesting is substantially ensured. If the camera 112 or some other meansof monitoring the distance to the user from the handheld device 100 thatcan generate an image of the user is used; then it is further possiblefor the handheld device 100 to ensure that the test is being undertakencorrectly. For example, in some vision tests, it is critical that theuser cover one eye and undertake the testing one eye at a time. In sucha case, the camera 112 can be used to monitor the user and ensure thatthe user has the correct eye covered for each test. The camera 112 canalso ensure that the same person is taking the test throughout the testsequence and the image of the user can be compared to images from pasttests to ensure that the person taking the test is indeed the correctperson. Other information, such as ensuring that the user taking thetest is awake and upright and is holding the handheld device at a properorientation can also be checked.

It is noted that for some testing the handheld device 100 mayautomatically compensate for differences in desired viewing distancesfor some or all of the tests provided. That is, by monitoring how farthe user is from the display 104, the handheld device 100 may compensatefor some variations in the viewing distance by adjusting the size of thetest image presented in the display 104 or by varying other aspects ofthe test image (for example, viewing distance may also be compensated tosome degree with the sharpness of the test image or by other factors).By automatically compensating for changes in viewing distance, thehandheld device 100 may make it easier for a user to take their test.Instead of compensating for viewing distance by altering the size orother features of the test image, the handheld device 100 may alsoaccount for alternative viewing distances by scaling the user'sresultant test score appropriately. And, of course, combinations of waysto automatically compensate for differences in viewing distance may alsobe applied.

Visible glare that may appear on the display 104 of the handheld device100 may be a substantial problem for accurate vision testing if itobscures test images and makes it difficult for the user to distinguishthe images provided on the display 104. Use of a matte finished display(or other type of display that reduces glare) to reduce glare may bebeneficial. In addition, the camera 112 may be used to sense ambientlight conditions and alert the user to reduce ambient light or move toanother location if too much ambient light is present that may result inglare or otherwise cause issues with vision testing. Scratches, smudges,chips, and other damage or contamination of the display 104 may alsomake accurate vision testing difficult. Use of a display 104 with a hardcoating to avoid damage or with a screen protection film may bebeneficial. As noted previously, a matte finish may be beneficial, so amatte finished screen protection film (or other glare reducing film) maybe desirable. Additionally, the handheld device 100 may at times remindthe user to clean and wipe off the display 104.

It is also possible to add auxiliary displays to the handheld device 100or to use the interface 118 or wireless connectivity to move imagesand/or video to an external video monitor. Auxiliary displays suitablefor use with the handheld device 100 include LCD display panels, CRTdisplays, light processing display devices, head mounted displays,binocular display devices, virtual reality viewers, and many other typesof displays. One example is use of the very small projectors that arenow available and can be incorporated into small devices and allowimages and video to be expanded for easy viewing. These small projectorsare sometimes referred to as pico-projectors. Such a pico-projector maybe physically integrated into the handheld device 100 or may be used asan external separate device connected to the handheld device 100 througha wired or wireless communication link.

If an auxiliary display is used, the handheld device 100 may includehardware and software to ensure that proper viewing distance and displayproperties are available so that a reliable test may be completed.Hence, while images used for regular purposes may be displayed on a widevariety of available displays, the handheld device 100 might only sendimages or video for vision testing to displays that it can ensure aresuitable for good quality testing. This requirement may impose the needfor additional connectivity to an auxiliary display and also additionalcalibration and security features if the auxiliary display is to be usedfor vision testing.

The functions of the handheld device 100 shown in FIG. 1 a may also beincorporated into electronic handheld devices that are already used forother functions. That is, the function delivered by the handheld device100 may be implemented on a portable game console, a cellular phone, apersonal digital assistant, a tablet computer, a netbook computer, anotebook computer, a blood glucose meter, or many other electronicdevices. It is noted that there may be some benefit to using deviceswith somewhat larger displays as a greater area of the retina can becovered in vision testing (this may be more important for some visiondisorders, but will be less important for others). However, largerdevices with larger displays are normally less portable and may be moreexpensive, so tradeoffs of cost and convenience versus retina testcoverage may need to be made. The ability to combine many functionstogether into a single device allows for convenience for the user andalso allows for beneficial combined functionality in some cases. Forexample, if the handheld device 100 of FIG. 1 a includes the function ofa glucometer, the user can record their blood glucose level when eachvision test is taken so that a more complete record of vision capabilityand blood glucose can be generated (and this may be especiallybeneficial to users at risk with regard to diabetic retinopathy). If thehandheld device includes a positioning technology such as the GlobalPositioning System (GPS), the records of vision testing can be locationstamped so that the user can more easily remember where they took eachtest and what the testing conditions were. Of course, the handhelddevice 100 can easily include calendar and clock functions so that testresults may also be time and date stamped.

In FIG. 2 a, a Landolt C 408 test image is shown. The Landolt C 408 testis suitable for use with the handheld device 100 already described. Thetest image includes a display 104 outer boundary 402, soft keys 404, andreference lines 406. In this test, the Landolt C 408 is rotated in 90degree increments so that the “open” side of the “C” points to the right(as shown in FIG. 2 a), to the left, upwards, or downwards. The userperforms the test by pressing the soft key 404 in the direction in whichthe Landolt C 408 has its opening. The Landolt C 408 test provides for avision acuity check. The test can be easily extended to includeadditional angles of orientation for the directions in which the “open”side of the “C” can appear in the course of a test. As noted previously,it is important that the Landolt C 408 test be conducted at anappropriate viewing distance. The display 104 outer boundary 402 is thelimit of the display 104 area used for the test. It is noted thatdepending on the actual design of the handheld device 100, the outerboundary 402 may be less than the physical limit of the display 104. Forexample, to test for a high level of vision acuity, the Landolt C 408may appear rather small in the handheld device 100 display 104, so theentire display 104 area may not be used for some tests. The referencelines 406 are optional for the Landolt C 408 test and are included tobetter define the region in which the Landolt C 408 is rotated. Also, itis noted that the soft keys 404 may be pressed manually by the user withtheir fingers or with a stylus if that is preferred. And, instead ofusing the soft keys 404 for the user to provide their input on theorientation of the Landolt C 408, this may be indicated by touching thetouch-screen at a pre-defined location (perhaps in the “opening” of theC), by strokes on the touch-screen, by gestures monitored by the camera112, by movements of the handheld device 100, through voice signals, orby other techniques.

The Landolt C 408 test is based on a user's ability to distinguish theorientation of the “C” as a function of how large the image ispresented. Of course, many other shapes may be used to create similartests. Another common similar test is known as the “tumbling E” test.The “tumbling E” test is very similar to the Landolt C 408 test, theonly key difference being the use of a letter E instead of a letter C.Of course, a very wide variety of shapes, such as circles, squares,triangles, and many other shapes that include some distortion,modulation, or other feature that allows their orientation to bespecific so that a user can be challenged to identify it.

In FIG. 2 b an Amsler Grid test image is shown. The Amsler Grid consistsof grid segments 412 arranged in a regular rectangular grid within theouter boundary 402. A center feature 414 is provided for the user undertest to fixate on while identifying any missing, wavy, or distorted gridsegments 412. With a touch-screen capability in the display 104, it isvery easy for the user to indicate which grid segments 412 are missing,wavy, or distorted simply by pressing on the display 104 above such agrid segment 412. With multi-touch capability in the display 104, theuser may be able to indicate the location of missing, wavy, or distortedgrid segments even more quickly and conveniently. It is possible toseparately track which grid segments 412 appear to be missing, wavy, ordistorted and this information is useful in keeping track of the statusof an eye disease over subsequent tests. That is, a missing grid segment412, may signal a more severe or advanced condition than a wavy ordistorted grid segment 412, so information for each level of conditioncan be collected separately and tracked automatically. The soft key 404shown in FIG. 2 b can be used to indicate that the user sees all gridsegments 412 normally. It is also noted, that the Amsler Grid test, likeall tests described here, can be performed with different lightintensities, colors, feature sizes, line weights, contrasts, and otherimage parameters to test the sensitivity and capability of the user'svision in a wide array of conditions.

FIG. 2 c shows an image for vision testing that includes a right circle420 and a left circle 416 either of which may include a modulated region418. The outer boundary 402 serves the same function as in the priorfigures. The soft key 404 is pressed by the user under test to indicatewhich of the two circles, the right circle 420 or the left circle 416has a modulated region 418. Of course, this selection can be donedirectly by touching the circle that has a modulated region 418 if atouch-screen display is used. And other methods of capturing this inputfrom the user based on visible gestures, movement of the handheld device100, sounds, etc. are also possible. By changing the amplitude andlocation of the modulated region 418 and whether it appears on the leftcircle 416 or the right circle 420 it is possible to determine theuser's ability to differentiate the presence or absence of a modulatedregion 418. Of course, other shapes besides circles such as hexagons,squares, and other shapes can be used. And the modulated region 418 neednot be a smooth curve as shown in FIG. 2 c, but may be triangular,rectangular, or of other shapes. The modulated region 418 may alsoappear at any angle around the circle including the top, the bottom,either side, or at other angles. And, of course, different colors, lineweights, contrasts, brightness levels, and other factors may be variedso that the user under test's ability to distinguish the modulatedregion 418 under varying conditions can be determined. Depending on thedisplay 104 size and format, the circles may be placed in any locationon the display and not to the right and left as shown in FIG. 2 c. Andadditionally, while FIG. 2 c shows two circles, it is possible to createa similar test using three, four, or any number of circles or othershapes. With a larger number of circles or other shapes used in visiontesting, the user selects from a broader number of choices and this maycreate a test with desirable attributes (the test may run faster, havemore redundancy, be more accurate, or have other desirable attributes).It is also possible to use a single shape, such as the modulated leftcircle 416 shown in FIG. 2 c with modulated region 418 in the manner ofthe Landolt C 408 test already described. In such a test, theorientation of the modulated region 418 is changed along with theamplitude of the modulation 418 and/or the size of the left circle 416as the user's ability to properly distinguish the orientation ismonitored.

In addition to the static images shown in the vision test in FIGS. 2 a-2c, it is also possible to use dynamic images for vision testing on thehandheld device 100. Images that open or close (expand or contract), ormove in other ways can be observed and/or compared to other dynamic orstatic images to help test for vision capability.

FIG. 3 a shows an image for vision testing suitable for use on ahandheld device 100 made up of multiple shapes in which one shape, acircle 420, is different from the other two, which are hexagons 424. Thedisplay boundary 402 is shown for reference. In this vision test, theuser selects the shape that is different from the other two by touchingit on a touch-screen display 104. Of course, this input could also bedone with a keyboard, mouse, cursor controller 110, soft keys, audiblesignals, gestures, movement of the handheld device 100, or by othertechniques. It is notable that in the image of FIG. 3 a, there is nopoint of fixation at which the user must concentrate their vision. Infact, the purpose of such a test is to force the user to employ theirbroader vision capability in identifying which of the three or moreshapes is different from the others.

Once the user selects which of the shapes in the image shown in FIG. 3 ais different from the others, in the embodiment as shown it is clearlythe circle 420, a subsequent test image may be presented to the user.This subsequent test image may be similar to the embodiment shown inFIG. 3 b. Note that FIG. 3 b, like FIG. 3 a, includes a display boundary402, a circle 420 and two hexagons 424. However, the locations of thecircle 420 and hexagons 424 have shifted inside the display boundary402. This is done intentionally to avoid the user fixating on onelocation in the test image and to encourage use of the user's broadervision. As with FIG. 3 a, the user when viewing FIG. 3 b would onceagain correctly select the circle 420 as the shape that is differentfrom the other two.

While FIGS. 3 a and 3 b used circles 420 and hexagons 424 for shapes tobe compared, may different shapes may be used. Squares, triangles,octagons, rectangles, and many other shapes can be applied. And whilethe circles 420 and hexagons 424 were relatively easy to distinguishfrom each other, shapes may be used that have only subtle differences sothat the user is challenged to discriminate between them. In a visiontest, a variety of easier and more difficult challenges in shapediscrimination may be presented to the user so that the user'scapability to detect small differences in shapes can be assessed. Thesubsequent images used for such testing may progressively become moredifficult to distinguish as testing progresses, they may become moredifficult based on some rules regarding the ability of the user todiscriminate shapes in prior images, or may even be presented to theuser randomly. Very many sequences for presenting more or less difficultshapes to discriminate are possible. It is also possible to make use ofshapes that are turning, moving, changing size, rotating, or otherwisebeing altered in time as the test is taken.

In FIG. 4 a, a circle 604 is shown that has pre-defined contrast as afunction of radial dimension. The circle 604 is shown as a lightcircular region on a gray background. It also includes dark halos 610and light halos 612 on both the inside and outside of the light circularregion. It is noted that the contrast level of the dark halos 610 andthe light halos 612 are a function of the radial dimension of the pointof consideration on the halo to the center of the circle 604. The use ofa circle 604 that has pre-defined contrast as a function of radialdimension is beneficial in further encouraging the user of a visiontesting system to avoid a specific point of fixation and insteademploying their broader vision capability. Use of shapes withpre-defined contrast as a function of radial dimension also relaxes thedependence of test results on viewing distance. Hence, if shapesincluding pre-defined contrast such as the circle 604 of FIG. 4 a wereused in the test described in FIGS. 3 a and 3 b, some benefit in theaccuracy of the testing may be achieved. Of course, many shapesincluding pre-defined contrast may be used instead of circles. Squares,triangles, ovals, ellipses, and many other shapes may be used. Also, theshapes need not be regular (that is, irregular shapes may also be used)and it is not even needed that they be closed curves. And, in additionto varying contrast with radial dimension, other aspects of the shapesuch as how sharp or fuzzy the lines are, brightness, color, and anyother aspect of how the shape is presented may be varied.

In FIG. 4 b, a modulated circle 608 is shown that has pre-definedcontrast as a function of radial dimension. The modulated circle 608 isshown as a light region on a gray background. It includes dark halos 610and light halos 612 on both the inside and outside the light region. Themodulated circle 608 of FIG. 4 b is very similar to the circle 604 ofFIG. 4 a with the exception that it has a modulated radius and is not aregular circle. Note that when the modulated circle 608 was formed, thepre-defined contrast as a function of radial dimension was applied firstand the circular shape was then modulated so that both the light regionand the dark halos 610 and light halos 612 were all modulated alltogether. The modulation applied in FIG. 4 b is a smooth curving changein radius as a function of angle, but many other modulations such astriangular modulations of radius, sinusoidal modulations of radius, andmany other modulation functions can be applied. It is also possible tocreate irregular shapes and even shapes that are not closed curves forshape discrimination testing.

In FIGS. 5 a, 5 b, and 5 c a sequence of vision test images 700 that maybe utilized on the handheld device 100 are shown. These would normallybe shown to a user in turn and the next image would be shown once theuser responds to the image being shown to them presently. The testimages 700 are three-way selection shape discrimination tests. In thefirst test image 700 shown in FIG. 5 a, two circles 604 and a modulatedcircle 608, all of which have pre-defined contrast as a function ofradial dimension, are shown. Similar to the vision test described inFIGS. 3 a and 3 b, the three-way shape discrimination test image 700 isviewed by a user who selects which of the three or more shapes (in thisembodiment three shapes are shown, but more can be used if desired) thatis different from the others. This selection may be done by touching thedisplay 104 over the shape being selected if a touch-screen ormulti-touch display is used, or may be done with buttons, a mouse,cursor controls, audible inputs, gestures, or other techniques. In theembodiment shown, the different shape is clearly the modulated circle608. In FIG. 5 b, there are still two circles 604 and one modulatedcircle 608, but the modulation level of the modulated circle 608 hasbeen reduced so that it is harder to distinguish from the circles 604.The order of the shapes has been changed so that the user must recognizethat the modulated circle 608 is now to the right and no longer in thecenter location as it was in FIG. 5 a and the relative location of allthe shapes has been shifted slightly upwards, downwards and/orside-to-side to avoid causing the user to fixate at a specific point inthe image. In addition, the modulation phase has been changed randomlyto minimize the cues of localized deviation from circularity from onetest trial to another. That is, the modulated circle 608 has also beenrotated randomly so that the phase of the modulation may not provide anyvisual cues. As testing progresses, the user may then be shown the testimage of FIG. 5 c in which the modulated circle 608 is now to the farleft and the modulation level is very small so that it is ratherdifficult to notice that it is different from the circles 604.

The vision testing approach shown in FIGS. 5 a, 5 b, and 5 c offersseveral advantages. First, since it is desired that the user not fixateon a specific point in the images, there is no loss of accuracy if theuser shifts their vision. In fact, it is desirable that the user makeuse of their broader vision. Second, the use of shapes such as thecircle 604 and the modulated circle 608 that have contrast that varieswith radial dimension makes the test less sensitive to small blurs inthe display 104 that may be caused by manufacturing defects, dust,smudges, streaks, or other dirt and contamination. Also, since theshapes used in the images are intentionally blurred (by the radialvariation of contrast), the test is less sensitive to imperfections ofthe visual accommodation of the user (that is, whether or not the userhas good focusing ability and has a proper lens prescription if needed),and for substantially the same reasons, the test is also less sensitiveto viewing distance from the user to the display 104. The embodimentshown in FIGS. 5 a, 5 b, and 5 c used circles 604 and modulated circles608, but other shapes (such as squares, triangles, irregular closed andopen curves, etc.) that are somewhat blurred, have halos, have variablecontrast, have shading, have lighter and darker pixels, or are otherwisemade somewhat fuzzy may also provide good results as vision test images.And, of course, such shapes may be presented in a wide variety ofcolors, contrast levels, brightness levels and with other alterations totheir construction and presentation.

FIG. 6 shows a flow chart 800 showing some elements of how a vision testroutine may be controlled through a computer program. While many programcontrol flows are possible for the operation of the handheld device 100,several novel features of the flow chart 800 are included to help ensureaccurate and reliable testing results. First step 802 indicates thebeginning of the flow chart and the INPUT line 804 indicates that ID(identification) information for the user of the system and profileinformation about that person is made available to the program. Thisinformation may be received from prior inputs from the user, otherprograms, configuration information loaded by a health care provider orcomputer system administrator, over the internet, or via other means.First control step 806, may check the user's ID against the informationreceived by the program from the INPUT line 804 and may verify theuser's identity. The identity information used may include a photographof the user, a password, electronic fingerprints, or other methods ofverifying identification. Since the handheld device 100 may include acamera, fingerprint sensor, fundus camera, and means to collect otherbiometric data, there are potentially many ways to verify the user'sidentification. In addition to purposes for verifying the user'sidentification, this biometric data may be collected and stored in thehandheld device to note the user's condition of health. Additionally,the biometric data may be date-stamped so that it can be associated tothe user's health condition at a particular time and associated withparticular vision testing results. Examples of biometric data include,without limitation, pupil dilation, iris color, eyelash growth, heartrate, blood pressure, ptosis, and results of other health conditionmeasurements. Much of this biometric data can be assessed with thecamera, but some may require to be collected through other auxiliarydevices as well. In second step 808, user information may be updatedonce the user's identification has been verified. The user informationmay include information such as their preferred language, age, race,sex, blood pressure, glucose reading, resting heart rate, weight,medications, dosage levels, and other health related information.Biometric information, the results of health measurements and/or medicaltests, the time and date of the dosage levels at which medications havebeen administered, side-effects the user may be experiencing frommedications or treatments, and observations or comments the user mayhave regarding their state of health may be updated in second step 808as well. Some of this information may come from an auxiliary device suchas a glucometer, medication dosing aid, or other instruments and may beentered into the handheld device either manually by the user orautomatically through an electronic interface. Medication dosing couldalso be recorded by the handheld device as a video to create a record ofeach medication dosing. The user information may also include otherinformation about the user such as their email address, phone numbers,information regarding how to contact their health care provider, andother information the handheld device 100 may need to facilitate carefor the user. It is noted that users may be likely to achieve the mostaccurate results when using their most comfortable language, hence,multilingual support based on the available user information may beimportant for the handheld device 100.

First control step 806 may also check to ensure that the software loadedon the handheld device 100 is a recent version and has not expired. Thehandheld device's 100 software may include expiration dates or a totalnumber of times the software can be used before it is mandatory that thesoftware be updated. This is an important safety feature as it ensuresthat old versions of the software cannot be used for a long time. Oldsoftware may have bugs that have been corrected in newer versions ornewer software may have enhancements that make the vision testing moreaccurate, reliable, or beneficial in other ways. If the software versionoperating on the handheld device has expired or is not usable for someother reason, first control step 806 may pass control to exceptionhandling service routine 828, where the user may be directed to downloadupdated software, request customer service, or otherwise address thesituation. It is noted that automatic software updates may also beprovided and the handheld device 100 may simply access the internetaccording to a regular schedule and check for possible updates to bedownloaded and installed. Alternatively, if specific handheld devices100 are registered with a host computer system, updates may be sent tothe specific handheld devices 100 as soon as they are ready for use.

Second control step 810 pretests, determines light levels, andself-tests handheld device 100. The pretest may be included to verifythat the user is in a correct state to allow a valid vision test to becompleted. This may be important to ensure that the user is alert,awake, not under the influence of medications, drugs, or alcohol, and isgenerally ready for the vision test. The pretest may be a short game,coordination check, or other check where the result is compared to pastresults for the user from prior testing. At this point in the program,the handheld device 100 may check the ambient light levels to ensurethat the user is in an environment adequate for the vision testing. Thismay normally be done using the camera 112 to sense the ambient lightlevels, but may also be done with other light detectors such as aphotodiode. Second control step 810 may also include a device self-test.In a self-test, the handheld device 100 may check its memory for properfunctionality, and may check its interfaces and operating parameters foracceptable conditions. The self-test may direct the user to further testor calibrate the handheld device 100 if a problem is detected.

If second control step 810 has a valid outcome, a user-specific visiontest or a standard test may be generated or accessed by the systemsoftware. The profile information from the INPUT line 804, the userinformation received in the second step 808, and possibly results fromprior vision tests for the user may be used to determine what visiontests should be included. For example, a user with macular degenerationmay benefit most from different tests than a patient with diabeticretinopathy. A user specific test generation is generated in third step812 and once the user specific test is ready, fourth step 814 runs thetest while monitoring the user's viewing distance, which eye the userhas covered, and possibly other parameters. These other parameters mightinclude monitoring an accelerometer or other motion sensor to sense ifthe user is shaking or otherwise moving more than would be acceptablefor an accurate test result. It may also include monitoring of theambient light levels, and/or checking for the presence of glare. Thetime the user takes for each test input may also be monitored so thatinterruptions of the testing or very long response times may be noted aspossible indications of an invalid test. If any situations arise duringthe vision test that may compromise the accuracy of the results, theuser may be notified to correct them. And if a correction is not made,the results may be marked to indicate they were received underquestionable operating circumstances.

Some means to allow the user to pause or abort testing may be includedin fourth step 814 functions, and also, may be included in other areasof the flow chart 800 as well. This is beneficial as the user may beinterrupted with a phone call, visitor, or have some other reason towant to stop testing immediately and resume later. The ability to pauseand resume testing may be limited to short interruptions as thereliability of the test may be compromised if the user's condition,ambient conditions, or other factors have changed since testing waspaused. Consequently, a time out function may be necessary if a pausefeature is included. It is noted that records of partial tests, abortedtests, and paused tests (whether or not they timed out) may be stored inthe handheld device 100, but should be properly recorded to ensure thatthey are not confused with valid and complete test results.

Third control step 816 checks to ensure that results from the test runin step 814 are reliable. This includes checking to ensure that all theparameters being monitored during the course of the test, such asviewing distance and proper eye coverage, etc., are nominal. And it mayalso include analysis of the test results to ensure consistency. Thatis, the vision test may be designed to include some redundancy intesting so that user responses on various tests are consistent with eachother and indicate that the user took the test properly and was notguessing, making random inputs, or otherwise taking the testcapriciously. One way this may be achieved is to occasionally presentthe user with a “freebie” test. That is, while the normal course of avision test may be to subsequently make it more difficult for the userto distinguish the features of the test image (this was illustrated inthe explanation of FIGS. 5 a, 5 b, and 5 c), it may be beneficial tooccasionally give the user a rather easy test image to respond to. Thisis referred to as a “freebie”. If the user doesn't quickly andaccurately respond to the “freebie” it may be a sign that the user isnot taking the test actively, is tired, or is somehow otherwiseimpaired. Additionally, occasionally offering the user a “freebie” testimage may help the user maintain confidence and keep trying to masterthe test.

Third control step 816 may also check specifically for false negativetest results. False negative results are especially troublesome as theymay indicate to the user that their condition is okay, when they mayactually have a vision condition that needs attention. A false negativemay be the result of the user cheating on the test by moving thehandheld device 100 closer to them than they should for some testdecisions, studying the test image for a long time, asking a person withthem what answer to provide, and possibly other ways. Additionally, afalse negative may occur if the test is not specifically sensitive tothe user's condition or possibly for other reasons. For this reason, itmay be important to ensure that all operating parameters (usercondition, ambient light conditions, response timing, etc.) areconsistent with accurate testing before a negative test result isprovided.

If the results appear to be reliable, third control step 816 passescontrol to fourth control step 818 which may determine whether the testresults show a significant change in vision. As noted previously, asubstantial benefit of vision monitoring may be gained in noting ifchanges in a user's vision have occurred from previous testing. Hence,fourth control step 818 may check specifically for this and direct theprogram to fifth control step 820 which checks if an additional test isneeded if significant changes may have occurred. If fifth control step820 finds that prior test results are not consistent (or if there are noprior results to compare to), a new user-specific test may be generatedby third step 812 so that the user is not influenced by remembering howhe or she responded to the prior test. That is, while the additionaltest may substantially test for the same conditions as the prior test,it may be presented so that the results are not influenced by the user'sperceptions from the prior test. Fourth control step 818 and fifthcontrol step 820 may also make other assessments. For example, if thisis the first time a new user is receiving the test, it may directcontrol to complete multiple tests simply to verify consistency of thetest readings and to more rapidly build a database of results for theuser.

If acceptable results are found so that no additional tests are needed,fourth control step 818 passes control to fifth step 822 where a dataarchive kept in the handheld device 100 may be updated with the newresults and results may be provided to the user. Once again, if fourthcontrol step 818 indicates a change in the users test results, controlpasses to fifth control step 820 where the results of the previous test,if one has already been completed, are compared to the results of thepresent test. If a sufficient number of tests (the system could beconfigured for any number of additional tests as desired) showconsistent results, control also passes on to fifth step 822 for dataarchiving and presentation of the results to the user.

Fifth step 822 may perform two very important functions. First, itupdates the data archives kept in the handheld device 100. The archivesmay include all information about the testing that was just completed.For example, the date and time the test was taken, identification of thehandheld device 100 used, where the test was taken (if positioninformation is available), how the user's identification was validated,a picture of the user, the room conditions, the distance from the userto the handheld when the test was taken, the time taken for and theresult of each response the user gave in the course of the test, thelength of any pauses in the testing, any invalid results, any specialconditions that arose, the results of all tests given, and otherinformation may be archived. Additional information such as screen shotsof the handheld device's 100 display 104 at various points of thetesting, and especially the screen shot presented to the user providingthe results of their test, may also be archived. Of course, additionalparameters may be archived, or for some embodiments, it may not benecessary to include all the information listed here. In any case,however, sufficient information may be archived so that a substantiallycomplete and accurate record of the testing is kept.

The second key function of fifth step 822 may be to notify the user ofthe results of his or her test. This may be done visually on thehandheld device 100 display 104, audibly, or by other means. But in anycase, the results provided to the user may include their specific testscores and also some information about what the scores mean. That is,the handheld device 100 may assure the user that their scores are withinreasonable bounds of their past scores. Or, if the user's vision haschanged such that the handheld device 100 concludes that a professionalevaluation is warranted, the handheld device 100 may direct the user tocontact their health care provider for an evaluation. Of course, thehandheld device 100 may also be used to keep track of the user'sappointments including their scheduled visits with healthcare providers.So in some cases, the handheld device 100 may produce normal results forvision testing, but still remind the user that they have a regularappointment with a healthcare professional.

Additionally, it may be beneficial to pass inspirational or encouragingmessages to the user. As it has been scientifically demonstrated that apositive outlook leads to better physical health, the user may benefitif they are given positive encouragement in the course of their testingand especially when their results are provided to them. Otherinformation that may be beneficial to the user such as recommendationsfor a healthy diet with exercise, advertising and branding information,or other information may also be passed to the user from the handhelddevice 100 at multiple points through the course of its use and, inparticular, when the user is provided and/or is about to be providedtheir testing results. Of course, the inspirational and other messagesmay be tailored to the user's specific preferences through informationstored in the handheld device 100. For example, if it is known to thehandheld device 100 that the user is trying lose weight, someencouragement consistent with this goal may be especially beneficial.Similarly, if the user's religion is known, inspirational messages canbe tailored to be appealing to them more specifically.

Control then passes from fifth step 822 to sixth step 824 where thetesting results may be uploaded to a healthcare provider, clinical studycoordinator, or other appropriate entity. The testing results may alsobe uploaded to a data server. Users with especially acute conditions,for example, may want a professional to review their testing results onan ongoing basis. Or, since the handheld device 100, could be damaged,destroyed, lost, or stolen, the user may want their results to be storedon a computer system server so that they can be recovered if needed. Ineither case, wired or wireless networking technology such as DSL, fiberoptics, wireless LAN, wireless WAN, or other wired or wireless datatransmission technologies may be used to upload the data. Some user'smay want email messages with their test results sent to specific emailaddresses and than can also be completed in sixth step 824 if desired.

It is also possible for data uploaded from the handheld device 100 to beused in the construction of databases of information that may be used toenhance knowledge of various testing and treatment routines. That is, ifa user is known to be taking certain medication, uploading and analyzingtheir vision testing results allows comparison of their results withothers so that a substantially complete and accurate knowledge of theeffectiveness of certain treatments may be assessed. This informationmay be beneficial to developers of treatments and especially in theconduction of medical trials to assess the efficacy of treatments. Inaddition to the scientific benefits of such data collection, businessmodels in which companies or individuals wanting access to certain datamay financially compensate a handheld device 100 user, or a provider ofvision testing technology, may also be possible. As an example, a healthinsurance provider may incentivize users to take regular tests andpossibly also upload their test results in the interests of makingoverall disease management and/or treatment more cost effective.

In the course of the program running the vision testing on the handhelddevice 100 as shown in the flow chart 800 in FIG. 6, several controlsteps pass control to exception handling service routine 828. Firstcontrol step 806, second control step 810, and third control step 816all include conditions for which negative or invalid results result insending control to exception handling service routine 828. Depending onthe nature of the invalid or negative result, and depending onelectronic diagnostics and self-testing the handheld device 100 performson itself to ensure proper operation, exception handling service routine828 may direct the user to perform different functions so that propertesting can resume or be initiated. For example, if the user'sidentification fails, exception handling service routine 828 may simplynotify the user and allow them to try again. However, if the self-testof the handheld device 100 has failed, the user may be directed to test,service, or calibrate the handheld device 100. Other conditions may bedealt with in appropriate manners as well. If the room ambient light istoo bright, the user may be directed to change it. If inconsistent testresults were determined and the test was deemed unreliable, the user maybe notified and asked to take the test another time. If repeatedunreliable results occur, the user may be directed to seek aprofessional evaluation from their healthcare provider. Since thehandheld device 100 may make very many measurements and use very manytechniques to ensure an accurate and reliable test, it is not practicalto list many dozens or even hundreds of them here. However, the overallflow of the flow chart 800 makes it clear that the handheld device 100will use many techniques to ensure accurate and dependable results.

Once all testing, archiving, user notifications and other functions arecompleted, program control passes to seventh step 826 where operation isended and the program ceases operation until it is restarted. In somecases, the handheld device 100 may include alarm functions to alert auser that they have a scheduled vision test to complete. In such a case,the handheld device 100 may start up automatically and send audibleand/or visible or other signals to the user to remind them to take theirtest. The handheld device 100 may also include other calendar,appointment management, or other user convenience software.Additionally, it may be synchronized or updated by other calendarmanagement software so that the user may conveniently keep track oftheir personal appointments along with their testing schedule, heathcare provider appointments, medication schedule, reminders to takevitamins and/or exercise, and other aspects of their overall care.

FIG. 7 a shows a graphical result of a shape discrimination vision test900. The first trial image is represented by the first cross 901 whichis shown at an elevated modulation level as it is positioned at a highlevel on the vertical axis 902. Note that the vertical axis 902represents modulation level and this is clear in FIG. 7 a as the words“Modulation Level” are shown as a title on the vertical axis 902.Modulation level as shown in FIGS. 7 a and 7 b refers to the amplitudeof the modulation of a modulated shape such as the modulated circle 608of FIG. 4 b, or FIGS. 5 a, 5 b, and 5 c. Subsequent trials arerepresented in FIG. 7 a as progressing to the right along the horizontalaxis 904 that is also labeled with the word “Trial”. Each subsequenttrial is also represented by a cross 908 and the modulation level forthe next several trials are shown as decreasing with each subsequenttrial. This approach is beneficial as a very large modulation level maybe used for the first few trials so that the user intuitively learnsthat the modulation will decrease on subsequent trials if correctanswers are provided. Of course, as explained with regard to FIGS. 5 a,5 b, and 5 c, as the modulation level is decreased, it will eventuallybecome difficult to accurately determine a modulated shape versus anun-modulated shape (i.e. a shape with no modulation) so the user willinvariably make a mistake at some point. The mistake trial 912illustrates this and shows that if a mistake is made, the modulationincreases on a subsequent trial. Once correct responses to a trialresume, the modulation will again decrease on subsequent trials. It isnoted that an amount modulation increases 914 when a mistake is made maybe different from an amount modulation is decreased 916 when a correctanswer is entered. After some number of trials, an accuraterepresentation of the limit of the user's modulation threshold 906 maybe estimated. The modulation threshold 906 may be determined from thedata in a number of ways. One approach would be to take the modulationthreshold 906 to be the level at which an equal number of decreasing andincreasing modulation trials (i.e., an equal number of mistakes andcorrect result entries) are made over some number of past trials. Forexample, the modulation threshold 906 could be taken as the level atwhich an equal number of correct results and mistakes occurred over thelast four trials. The modulation threshold 906 might also be taken asthe modulation level that was crossed with correct (or incorrect)answers some fixed number of times. For example, in FIG. 7 a, themodulation threshold 906 is a level that was crossed three times withcorrect answers. The third correct crossing 918 in FIG. 7 a illustratesthis. Or the modulation threshold might also be taken as the mean ofseveral reversals (the level changes from correct to incorrect or fromincorrect to correct). Another way to determine the threshold might beto fit a mathematical function that describes the threshold behavior ofthe visual system to the percent correct rates at various testinglevels. The reliability of the threshold estimation may be assessed byanalyzing fitting parameters and by comparing threshold values obtainedwith various threshold determination methods.

FIG. 7 b shows a similar graphical result of a shape discriminationvision test 900 to that shown in FIG. 7 a, but freebie 920 and freebie922 are included. As previously described, a freebie trial is a trial inwhich the user is presented with a rather large modulation with theexpectation that it should be an easy test for them to answer correctly.Hence, observation of the user's replies to a freebie is one way ofensuring that the user is actively engaged in the test and isn't justguessing. Another measure of the user's ability to correctly take thetest is the consistency of the level at which mistakes occur as the testtrials progress. In FIG. 7 b, the first mistake trial 912, the secondmistake trial 924 and the third mistake trial 926 all occur at similarmodulation levels. Consequently, the confidence in the modulationthreshold 906 level for the user is relatively high as the user appearsto be consistent in the level of modulation reached before a mistake ismade. Other ways of assessing the user's consistency includeconsistently correct answers for higher modulation levels above themodulation threshold 906, and other possible statistical or othermathematical analysis techniques. It is noted that the amount themodulation is varied after the occurrence of a freebie may resume fromthe level of modulation prior to the freebie, may decrease from thelevel of modulation prior to the freebie assuming the freebie trial wasanswered correctly, or may follow other rules for variation ofmodulation including random variation of modulation rules and otherrules.

FIG. 8 a illustrates a quantitative result presentation 1000 forproviding results to the user and/or tabulating results of a shapediscrimination test. The L 1010 indicates that the results above it arefor the left eye and the R 1012 indicates that the results above it arefor the right eye. The % Mod Result for the left eye 1002 is themodulation threshold 906 shown in FIGS. 7 a and 7 b for the left eye ofthe user and the % Mod Result for the right eye 1006 is the modulationthreshold 906 for the right eye of the user. The % Mod Result for theleft eye 1002 and the % Mod Result for the right eye 1006 may bepresented as simple percentages of modulation, proportions of modulationto circle radius (or another key dimension whatever shape is used), inthe well-known MAR (Minimum Angle of Resolution) measure, or in log MAR(the logarithm of MAR), or in other quantitative or relative measurementformats. The left eye consistency score 1004 and the right eyeconsistency score 1008 are consistency measures as previously discussedfor the users left eye and right eye tests respectively. Providing aconsistency score of some sort to the user coaches them on their testtaking ability and reinforces the need to take the vision test carefullyand actively. The left eye consistency score 1004 and the right eyeconsistency score 1008 are much like video game scores in that they tellthe user how well they took the test. Storing the left eye consistencyscore 1004 and the right eye consistency score 1008 in the handhelddevice's 100 memory and making it a part of the test archive for theuser is useful as it provides an indication of how well the test wastaken, and hence, to what level the result may be trusted.

In FIG. 8 b, an example quantitative result presentation 1000 isprovided with numerical example results for the % Mod Result for theleft eye 1002 and the left eye consistency score 1004 shown above the L1010; and with % Mod Result for the right eye 1006 and a right eyeconsistency score 1008 shown above the R 1012. Note that the left eyeconsistency score 1004 and the right eye consistency score 1008 aspresented in FIG. 8 b are not numerical, but are represented as ++ and+, respectively, indicating relatively how consistent the user was intaking the tests. Numerical scores are also possible, but relativescores using stars, smiling or frowning faces, different colors, orother approaches may be beneficial in providing a general indication ofhow consistently the user took the test. Additionally, the % Mod Resultfor the left eye 1002 and the % Mod Result for the right eye 1006 mayalso be provided as relative scores if desired. Relative scores such asgood/moderate/poor, normal/borderline/abnormal, and many other relativescores are possible.

FIG. 8 c shows another example technique for result presentation. AlogMAR gray scale 1030 is shown including a title 1038, a lower grayscale limit 1036, an upper gray scale limit 1034, and a gray scale 1032.In FIG. 8 c, the title 1038 identifies the result presentation of thelogMAR gray scale 1030 as “logMAR Gray Scale”, the lower gray scalelimit 1036 is illustrated as “−1.00” and the upper gray scale limit 1034is illustrated as “1.00”. The gray scale 1032 shows a range from whitefor results near the lower gray scale limit 1036 to black for resultsnear the upper gray scale limit 1034. For example, a test score may berepresented by using a gray level between the upper gray scale limit1034 and the lower gray scale limit 1036. The accuracy of the test scoremay be represented by the extension of that gray level, or a band ofgray levels centered at the one that represents the test score. Thenarrower the gray level band, the more accurate or consistent the testscore. A wide range of other options for using a segment of gray regionwithin a gray scale 1032 include showing a result presentation in whichthe center of a gray region represents a test score and the size, shapeor other aspects of the gray region represent the consistency of theuser in taking the test. Of course, many variants including use ofvariable color shades instead of a gray scale 1032, varying shapes,sizes, and other variations may be used.

Although the description above contains many specificities, these shouldnot be construed as limiting the scope of the invention, but as merelyproviding illustrations of some of the presently preferred embodimentsof this invention. Thus the scope of the present invention should bedetermined by the appended claims and their legal equivalents, ratherthan by the examples given. Those skilled in the art to which thisapplication relates will appreciate that other and further additions,deletions, substitutions and modifications may be made to the describedembodiments.

What is claimed is:
 1. A method to self-test vision of a user for usewith a handheld vision tester, comprising: ensuring that a display ofsaid handheld vision tester is within an acceptable distance to eyes ofsaid user, wherein variations of said acceptable distance arecompensated for; displaying different shapes, either statically ordynamically, on said display to said user; and allowing for input tosaid handheld vision tester by said user in response to said displaying;determining results of said self-test from said inputs to said handheldvision tester by said user.
 2. The method as recited in claim 1, furthercomprising: analyzing said results of said vision tests to determine athreshold modulation level of said shapes and a consistency of saidresults; displaying said results to said user after said differentshapes have been displayed; and storing said results in said handheldvision tester.
 3. The method as recited in claim 2, wherein saiddisplaying said results include displaying said threshold modulationlevel for a left eye of said eyes and a right eye of said eyes.
 4. Themethod as recited in claim 3, wherein a consistency score is alsopresented for both said left and said right eye.
 5. The method asrecited in claim 2, wherein a log MAR measure of said results ispresented.
 6. The method as recited in claim 2, further comprisingtransmitting, by said handheld vision tester, said stored results to ahealthcare provider, clinical study coordinator, or other appropriateentity.
 7. The method as recited in claim 1, further comprisingmeasuring, by a camera integral to said handheld vision tester,dimensions of a face of said user to determine said acceptable distance.8. The method as recited in claim 7, wherein said dimensions include adistance between pupils of said eyes, a distance between outer eyesockets of said user, a distance between said pupils and a bottom of anose of said user, or a combination thereof.
 9. The method as recited inclaim 7, further comprising determining, by said camera, if said userhas an appropriate one of said eyes covered for said self-test.
 10. Themethod as recited in claim 1, wherein said different shapes include aLandolt C, tumbling E, or Amsler grid.
 11. The method as recited inclaim 1, wherein said display is a touchscreen display and said input inresponse to said different shapes is said user touching a portion ofsaid touchscreen display.
 12. The method as recited in claim 1, whereinone of said different shapes may be a modulated version of another shapedisplayed at the same time.
 13. The method as recited in claim 12,wherein an order of said one of said different shapes changes duringsaid self-test.
 14. The method as recited in claim 1, wherein saiddifferent shapes include a halo on an inside and/or outside edge of saiddifferent shapes.
 15. The method as recited in claim 1, wherein saiddifferent shapes include at least two similar shapes and at least oneother similar shape with edges modulated, each of said different shapesincluding a halo on an inside and/or outside edge of said differentshapes.
 16. The method as recited in claim 1, further comprisingrotating at least one of said different shapes during said self-test.17. The method as recited in claim 1, wherein easy shapes areinterspersed in time between said different shapes to ensure reliabilityand consistency.
 18. The method as recited in claim 1, furthercomprising verifying an identity of said user by entry of a user ID bysaid user.
 19. The method as recited in claim 1, further comprisingstoring, on said handheld vision tester, biometric informationreflecting health conditions of said user.
 20. The method as recited inclaim 19, further comprising storing a date and time when said biometricinformation is captured by said handheld vision tester.
 21. The methodas recited in claim 19, further comprising storing a date, time, anddosages of medications administered to said user.
 22. The method asrecited in claim 21, further comprising storing observations by saiduser of side-effects of said dosages of medications and other commentsby said user of a state of health of said user.
 23. The method asrecited in claim 19, wherein said biometric information includes pupildilation, iris color, eyelash growth, heart rate, blood pressure, orptosis.
 24. The method as recited in claim 1, further comprisingassessing ambient light during said self-test and compensating for alevel of said ambient light.
 25. The method as recited in claim 24,further comprising notifying said user to change said ambient light ifsaid level falls below or above a threshold.
 26. A handheld visiontester for vision self-testing by a user, comprising: a displayconfigured to present different shapes, either statically ordynamically, to said user for said vision self-testing; a cameraconfigured to ensure eyes of said user are within an acceptable distanceto said display, wherein variations of said acceptable distance arecompensated for; and a control configured to allow said user to: inputresponses to said displayed different shapes; trigger operations of saidhandheld vision tester; and control said handheld vision tester.
 27. Thehandheld vision tester as recited in claim 26, further comprising: aninterface port configured to transmit results of said visionself-testing
 28. The handheld vision tester as recited in claim 26,further configured to: analyze said results to determine a thresholdmodulation level of said different shapes and determine a consistency ofsaid results, wherein said display is further configured to display saidresults to said user after said different shapes have been displayed;and store said results in said handheld vision tester.
 29. The handheldvision tester as recited in claim 28, wherein said display is furtherconfigured to display said threshold modulation level for a left eye ofsaid eyes and a right eye of said eyes.
 30. The handheld vision testeras recited in claim 29, wherein said display is further configured todisplay a consistency score for both said left and said right eye. 31.The handheld vision tester as recited in claim 28, wherein a log MARmeasure of said results is presented.
 32. The handheld vision tester asrecited in claim 27, wherein said interface port is further configuredto transmit said stored results to a healthcare provider.
 33. Thehandheld vision tester as recited in claim 26, wherein said camera isconfigured to measure dimensions of a face of said user to determinesaid acceptable distance.
 34. The handheld vision tester as recited inclaim 33, wherein said dimensions include a distance between pupils ofsaid eyes, a distance between outer eye sockets of said user, a distancebetween said pupils and a bottom of a nose of said user, or acombination thereof.
 35. The handheld vision tester as recited in claim33, wherein said camera is configured to determine if said user has anappropriate one of said eyes covered for said vision self-testing. 36.The handheld vision tester as recited in claim 26, wherein saiddifferent shapes include a Landolt C, tumbling E, or Amsler grid
 37. Thehandheld vision tester as recited in claim 26, wherein said display is atouchscreen display and said input in response to said different shapesis said user touching a portion of said touchscreen display.
 38. Thehandheld vision tester as recited in claim 26, wherein one of saiddifferent shapes may be a modulated version of another shape displayedat the same time.
 39. The handheld vision tester as recited in claim 38,wherein an order of said one of said different shapes is changed duringsaid vision self-testing.
 40. The handheld vision tester as recited inclaim 26, wherein said different shapes include a halo on an insideand/or outside edge of said different shapes.
 41. The handheld visiontester as recited in claim 26, wherein said different shapes include atleast two similar shapes and at least one other similar shape with edgesmodulated, each of said different shapes including a halo on an insideand/or outside edge of said different shapes.
 42. The handheld visiontester as recited in claim 26, wherein at least one of said differentshapes rotates during said vision self-testing
 43. The handheld visiontester as recited in claim 26, wherein easy shapes are interspersed intime between said different shapes to ensure reliability andconsistency.
 44. The handheld vision tester as recited in claim 26,wherein in an identity of said user is verified by entry of a user ID bysaid user.
 45. The handheld vision tester as recited in claim 26,wherein said camera measures a size of pupils of said user during saidself-testing, and wherein said size is stored in said handheld visiontester.